Hermetic compressor

ABSTRACT

A hermetic compressor, in which an exhaust chamber part having an exhaust chamber therein is provided at a cylinder head, in place of a cylinder block, thus preventing deformation of the cylinder block and preventing a reduction in volume efficiency of gas. The exhaust chamber part has a chamber body integrally formed at the cylinder head, and a chamber cover to cover an open top of the chamber body. The chamber body has two bored cylindrical parts which are arranged in parallel to each other and integrally coupled to each other such that an exhaust chamber of the chamber part is divided into first and second chambers communicating with each other. The chamber cover has two dome-shaped parts which are arranged in parallel to each other and integrally coupled to each other so as to correspond to a shape of the chamber body. A first boss having a first bolt hole and a second boss having a second bolt hole are projected toward the chamber cover in the first and second chambers of the chamber body, respectively, and first and second through holes are formed in the chamber cover at positions corresponding to the first and second bolt holes, respectively, so that the chamber cover is mounted to the chamber body by use of bolts which are respectively tightened to the first and second bolt holes while passing through the first and second through holes.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of Korean Application No.2003-25567, filed Apr. 22, 2003, in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates, in general, to hermeticcompressors and, more particularly, to a hermetic compressor, in whichan exhaust chamber part to temporarily store therein compressed gasdischarged from a cylinder bore prior to exhausting the compressed gasto an outside of a hermetic casing of the compressor, is provided at acylinder head, in place of a cylinder block, thus preventing deformationof the cylinder block and allowing easy and simple production of thecylinder block.

[0004] 2. Description of the Related Art

[0005] As well known to those skilled in the art, hermetic compressorstypically have a compression unit to compress inlet gas, a drive unit tooperate the compression unit, and a hermetic casing to hermeticallyhouse the compression unit and the drive unit therein. The hermeticcompressors suck the gas into the hermetic casing, and compress the gas,prior to discharging the compressed gas to an outside of the hermeticcasing. The hermetic compressors are typically used in refrigerationcircuits of a variety of refrigeration systems, such as air conditionersand refrigerators, so as to compress low-pressure gas refrigerantreturned from an evaporator of the refrigeration circuit, thus producinghigh-pressure gas refrigerant and discharging the high-pressure gasrefrigerant to a condenser of the refrigeration circuit.

[0006] In the hermetic compressors, the compression unit includes acylinder block and a piston, while the drive unit includes a stator anda rotor. Examples of the hermetic compressors are hermetic linearcompressors and hermetic reciprocating compressors. In a conventionalhermetic linear compressor, a piston to which a rotor of a drive unit ismounted performs a rectilinear reciprocating action to compress the gas.In a conventional hermetic reciprocating compressor, a rotating shaftpenetrates a rotor of a drive unit and is connected to a piston, so thatthe piston performs a rectilinear reciprocating action in response to arotating action of the rotating shaft, thus compressing the gas.

[0007] In the conventional hermetic compressors, a cylinder blockdefines an axial cylinder bore therein. The cylinder bore of thecylinder block receives the piston therein, and defines a space thereinto compress the gas. A cylinder head is mounted to an upper end of thecylinder block to cover the cylinder bore.

[0008] The cylinder block, to which the cylinder head is mounted, isprovided with an exhaust chamber part to temporarily store therein thecompressed gas discharged from the cylinder bore, prior to exhaustingthe compressed gas to an outside of the hermetic casing of thecompressor. The exhaust chamber part has a chamber body which is coveredwith a chamber cover to define a predetermined exhaust chamber therein.

[0009] However, the conventional hermetic compressors having theabove-mentioned construction is problematic, as follows. That is, theexhaust chamber part is formed in the cylinder block, thus complicatingthe structure of the cylinder block and making it difficult to producethe cylinder block. In addition, it is necessary to lock the chambercover to the chamber body by tightening a plurality of bolts with hightorque to accomplish an airtight sealing effect at a junction betweenthe chamber cover and the chamber body. However, the high-torque lockingof the chamber cover to the chamber body of the exhaust chamber part byuse of the bolts may cause a deformation of the cylinder block, and,sometimes cause damage or breakage of the cylinder block.

[0010] Particularly, it is necessary to precisely arrange the piston inthe cylinder bore of the cylinder block with a minute clearance definedbetween the piston and the cylinder bore. However, when the cylinderbore is deformed during a process of bolting the chamber cover to thechamber body of the exhaust chamber part with the high torque, it isalmost impossible to precisely arrange the piston in the cylinder borewith the desired minute clearance defined between the piston and thecylinder bore. In such a case, the gas may leak in the cylinder borethrough a junction between the piston and the cylinder bore, or thepiston may be locked to an inner surface of the cylinder bore. When thepiston is locked to the inner surface of the cylinder bore, the pistoncannot perform a reciprocating action in the cylinder bore.

[0011] Furthermore, since the high-pressure and high-temperature gas istemporarily stored in the exhaust chamber part of the conventionalhermetic compressors, the cylinder block integrated with the exhaustchamber part is heated by the high-pressure and high-temperature gas toa high temperature, thus increasing the temperature of the inlet gaswhich flows into the cylinder bore. In such a case, the inlet gas isreduced in volume efficiency thereof, and the hermetic compressor isreduced in gas compression efficiency thereof.

SUMMARY OF THE INVENTION

[0012] Accordingly, it is an aspect of the present invention to providea hermetic compressor, in which an exhaust chamber part is placed at aposition free from causing deformation of a cylinder block, and whichallows easy and simple production of the cylinder block, without causinga reduction in volume efficiency of inlet gas sucked into the cylinderbore.

[0013] Additional aspects and advantages of the invention will be setforth in part in the description which follows and, in part, will beobvious from the description, or may be learned by practice of theinvention.

[0014] The foregoing and other aspects of the present invention areachieved by providing a hermetic compressor, including: a casing; acylinder block installed in the casing, with a cylinder bore defined inthe cylinder block; a piston placed in the cylinder bore so as toreciprocate in the cylinder bore; a cylinder head mounted to an end ofthe cylinder block so as to cover the cylinder bore; and an exhaustchamber part provided at the cylinder head so as to temporarily storecompressed gas discharged from the cylinder bore, and exhaust thecompressed gas to an outside of the casing.

[0015] The exhaust chamber part includes a chamber body integrallyformed at a side of the cylinder head, the chamber body being open at atop thereof to define an exhaust chamber therein; and a chamber cover tocover the open top of the chamber body.

[0016] The chamber body includes two bored cylindrical parts which arearranged in parallel to each other and integrally coupled to each othersuch that the exhaust chamber is divided into first and second chamberscommunicating with each other, and the chamber cover includes twodome-shaped parts which are arranged in parallel to each other andintegrally coupled to each other so as to correspond to a shape of thechamber body.

[0017] In the hermetic compressor, an exhaust pipe is provided at thechamber body at a position between the first and second chambers, thusexhausting the compressed gas from the first and second chambers to theoutside of the casing.

[0018] In the hermetic compressor, a first boss having a first bolt holeand a second boss having a second bolt hole are projected toward thechamber cover in the first and second chambers of the chamber body,respectively, and first and second through holes are formed in thechamber cover at positions corresponding to the first and second boltholes, respectively, so that the chamber cover is mounted to the chamberbody by use of bolts which are respectively tightened to the first andsecond bolt holes while passing through the first and second throughholes.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] These and other aspects and advantages of the invention willbecome apparent and more readily appreciated from the followingdescription of the preferred embodiments, taken in conjunction with theaccompanying drawings of which:

[0020]FIG. 1 is a longitudinal sectioned view of a hermetic compressor,according to an embodiment of the present invention;

[0021]FIG. 2 is an exploded perspective view of a part of the hermeticcompressor of FIG. 1 to show a cylinder head integrally provided with anexhaust chamber part, when the cylinder head is disassembled from acylinder block; and

[0022]FIG. 3 is a perspective view of the part of the hermeticcompressor of FIG. 1 to show the cylinder head completely assembled withthe cylinder block.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Reference will now be made in detail to the present preferredembodiments of the present invention, examples of which are illustratedin the accompanying drawings, wherein like reference numerals refer tolike elements throughout.

[0024]FIG. 1 is a longitudinal sectioned view of a hermetic compressor,according to an embodiment of the present invention. As shown in thedrawing, the hermetic compressor according to the present invention hasa hermetic casing 1 that hermetically houses a drive unit 10 and acompression unit 20 therein. The hermetic compressor thus sucks andcompresses gas, such as a gas refrigerant circulating through arefrigeration circuit of a refrigeration system, prior to dischargingthe compressed gas to an outside of the hermetic casing 1.

[0025] In the hermetic compressor, the compression unit 20 includes acylinder block 1, a cylinder head 23, a piston 24, a frame 25, aplurality of spacers 26, a resonant spring 27, and a movable member 28.The cylinder block 21 defines an axial cylinder bore 22 therein, and thegas is compressed in the cylinder bore 22. The cylinder head 23 ismounted to an upper end of the cylinder block 21 to cover the cylinderbore 22. The piston 24 is placed in the cylinder bore 22 such that thepiston 24 reciprocates in an axial direction to compress the gas in thecylinder bore 22. The frame 25 and the plurality of spacers 26 aremounted to a lower end of the cylinder block 21, while the resonantspring 27 is horizontally mounted to lower ends of the spacers 26. Themovable member 28 connects the piston 24 to the resonant spring 27. Asuction muffler 29 and an exhaust chamber part 40 are provided at bothsides of the cylinder head 23, respectively. A suction valve 30 and anexhaust valve 31 are provided in the cylinder head 23.

[0026] The drive unit 10 includes first and second stators 11 and 12, acoil 13, and a permanent magnet 14. The first and second stators 11 and12 are concentrically mounted around an outer surface of the cylinderblock 21, with a gap defined between the first and second stators 11 and12. The coil 13 is wound in an interior of the first stator 11. Thepermanent magnet 14 is installed on the movable member 28 which extendsinto the gap defined between the first and second stators 11 and 12,such that the permanent magnet 14 is moved along with both the piston 24and the movable member 28.

[0027] The drive unit 10 and the compression unit 20 are supported inthe hermetic casing 1 while being suspended by a plurality of coilsprings 2. When electric power is applied to the coil 13 during anoperation of the hermetic compressor, an electromagnetic field isgenerated along the first and second stators 11 and 12, so that thepermanent magnet 14 linearly reciprocates in a vertical direction due tothe electromagnetic field. Therefore, both the movable member 28 and thepiston 24 reciprocate in the vertical direction. In such a case, thereciprocating action of the piston 24 is enhanced by a resonance of theresonant spring 27.

[0028] During the reciprocating action of the piston 24, the suctionvalve 30 and the exhaust valve 31 are alternately opened. Therefore, gasis sucked into the cylinder bore 22 through the suction muffler 29 so asto be compressed, and is discharged from the cylinder bore 22 to theexhaust chamber part 40.

[0029] An arrangement of the exhaust chamber part of the hermeticcompressor according to the present invention will be described indetail herein below, with reference to FIGS. 2 and 3.

[0030]FIG. 2 is perspective views of a part of the hermetic compressorof the present invention, in which FIG. 2 shows the cylinder head whenthe cylinder head having the exhaust chamber part is disassembled fromthe cylinder block, and FIG. 3 shows the cylinder head completelyassembled with the cylinder block.

[0031] As shown in FIG. 2, the exhaust chamber part 40 is integrallyprovided at a first side of the cylinder head 23 which covers thecylinder bore 22 at the upper end of the cylinder block 21. The suctionmuffler 29 is provided at a second side of the cylinder head 23, whichis opposite to the first side of the cylinder head 23 having the exhaustchamber part 40. Due to the suction muffler 29 of the cylinder head 23,the gas is introduced into the cylinder bore 22 through the cylinderhead 23. The gas is compressed in the cylinder bore 22, and thecompressed gas is discharged from the cylinder bore 22 to the exhaustchamber part 40.

[0032] The exhaust chamber part 40 has a chamber body 41 and a chambercover 42. The chamber body 41 defining an exhaust chamber therein hastwo bored cylindrical parts which are each open at a top thereof and arearranged in parallel to each other while being coupled to each other.The chamber body 41 having the above-described structure is integrallyformed at the cylinder head 23. The chamber cover 42 is mounted to theopen top of the chamber body 41 to cover the open top of the chamberbody 41.

[0033] Therefore, the chamber body 41 has therein first and secondchambers 43 and 44 which communicate with each other and temporarilystore the compressed gas therein. The chamber cover 42, which covers theopen top of the chamber body 41, has two dome-shaped parts which arearranged in parallel to each other while being coupled to each other soas to correspond to the shape of the chamber body 41.

[0034] First and second exhaust ports 45 and 46 are formed in thecylinder head 23 at positions corresponding to the first and secondchambers 43 and 44, respectively, so as to guide the compressed gas fromthe cylinder head 23 into the first and second chambers 43 and 44. Anexhaust pipe 47 is formed at the chamber body 41 at a position betweenthe first and second chambers 43 and 44, thus exhausting the compressedgas from the first and second chambers 43 and 44 to the outside of thecasing 1.

[0035] In order to mount the chamber cover 42 to the open top of thechamber body 41 integrally formed at the cylinder head 23 by use of aplurality of bolts 54, first and second bosses 48 and 50 are projectedfrom a bottom of the chamber body 41 toward the chamber cover 42 in thefirst and second chambers 43 and 44 of the chamber body 41,respectively.

[0036] The first boss 48 has a first axial bolt hole 49, while thesecond boss 50 has a second axial bolt hole 51. The chamber cover 42 hasfirst and second through holes 52 and 53 at positions corresponding tothe first and second bolt holes 49 and 51, respectively.

[0037] Therefore, when the bolts 54 are tightened to the first andsecond bolt holes 49 and 51 through the first and second through holes52 and 53 with an appropriate torque, the chamber cover 42 is easily andsimply mounted to the chamber body 41 as shown in FIG. 3. The process ofbolting the chamber cover 42 to the chamber body 41 is performed withhaving no relation to the cylinder block 21, thus not deforming,damaging or breaking the cylinder block 21.

[0038] In the above-described embodiment, the present invention isadapted to a hermetic linear compressor. However, it should beunderstood that the present invention may be adapted to a hermeticreciprocating compressor, in addition to the hermetic linear compressor,without affecting the functioning of the present invention.

[0039] As apparent from the above description, the present inventionprovides a hermetic compressor, in which an exhaust chamber part totemporarily store therein compressed gas discharged from a cylinder boreprior to exhausting the compressed gas to an outside of a hermeticcasing, is integrally formed at a cylinder head, in place of a cylinderblock. It is thus possible to simplify the structure of the cylinderblock, so that the cylinder block is easily and simply produced.

[0040] In addition, a process of bolting a chamber cover to an open topof a chamber body of the exhaust chamber part is performed with havingno relation to the cylinder block, so that the process is free fromdeforming, damaging or breaking the cylinder block. It is thus possibleto precisely arrange a piston in the cylinder bore of the cylinder blockwith a minute clearance defined between the piston and the cylinderbore, so that gas leakage from a junction between the piston and thecylinder bore is prevented, and gas compression efficiency of thehermetic compressor is improved.

[0041] Furthermore, since the exhaust chamber part of the presentinvention is provided at the cylinder head, in place of the cylinderblock, heat of the compressed gas temporarily stored in the exhaustchamber part is scarcely transmitted to the cylinder block. Therefore, atemperature of inlet gas which flows into the cylinder bore is notincreased due to the cylinder block, so that volume efficiency of theinlet gas and gas compression efficiency of the hermetic compressor areimproved.

[0042] Although a preferred embodiment of the present invention has beenshown and described, it would be appreciated by those skilled in the artthat changes may be made in these embodiments without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

What is claimed is:
 1. A hermetic compressor, comprising: a casing; acylinder block installed in the casing, with a cylinder bore defined inthe cylinder block; a piston placed in the cylinder bore so as toreciprocate in the cylinder bore; a cylinder head mounted to an end ofthe cylinder block so as to cover the cylinder bore; and an exhaustchamber part provided at the cylinder head so as to temporarily storecompressed gas discharged from the cylinder bore, and exhaust thecompressed gas to an outside of the casing.
 2. The hermetic compressoraccording to claim 1, wherein the exhaust chamber part comprises: achamber body integrally formed at a side of the cylinder head, thechamber body being open at a top thereof to define an exhaust chambertherein; and a chamber cover to cover the open top of the chamber body.3. The hermetic compressor according to claim 2, wherein the chamberbody and the chamber cover of the exhaust chamber part are provided withat least one bolt hole and at least one through hole, respectively, sothat the chamber cover is mounted to the chamber body by use of a boltwhich is tightened to the bolt hole while passing through the throughhole.
 4. The hermetic compressor according to claim 2, wherein thechamber body comprises two bored cylindrical parts which are arranged inparallel to each other and integrally coupled to each other such thatthe exhaust chamber is divided into first and second chamberscommunicating with each other, and the chamber cover comprises twodome-shaped parts which are arranged in parallel to each other andintegrally coupled to each other so as to correspond to a shape of thechamber body.
 5. The hermetic compressor according to claim 4, whereinan exhaust pipe is provided at the chamber body at a position betweenthe first and second chambers, thus exhausting the compressed gas fromthe first and second chambers to the outside of the casing.
 6. Thehermetic compressor according to claim 4, wherein a first boss having afirst bolt hole and a second boss having a second bolt hole areprojected toward the chamber cover in the first and second chambers ofthe chamber body, respectively, and first and second through holes areformed in the chamber cover at positions corresponding to the first andsecond bolt holes, respectively, so that the chamber cover is mounted tothe chamber body by use of bolts which are respectively tightened to thefirst and second bolt holes while passing through the first and secondthrough holes.